1. Field of the Invention
The present invention relates to a technical field of radiation inspection, more particularly, relates to a gantry configuration for a combined mobile radiation inspection system.
2. Description of the Related Art
In prior art, a gantry combined mobile radiation inspection system is a large container/vehicle radiation inspection system, and a core technology of which is a radiation imaging technology. The gantry combined mobile container/vehicle radiation inspection system is a container/vehicle safety inspection system used in seaport, border, airport, etc., and has a special modular design in structure, therefore, it can be simply assembled and disassembled, without a need to construct a fixed protection construction, and without a need to construct a radiation protection wall. An imaging device of the gantry combined mobile container/vehicle radiation inspection system is a gantry arm frame. The container/vehicle to be inspected is located below the gantry arm frame and in the middle of fixed rails. The gantry arm frame moves on the fixed rails. A ray emitted from a radiation source provided on one side arm frame passes through the inspected container/vehicle and is received and processed by a radiation detector provided on the other side arm frame, so as to form a scan image.
The gantry arm frame moves on the fixed rails and is constrained by the fixed rails, and basically it cannot derail from the fixed rails. Accordingly, in the prior art, a synchronization problem about moving speeds of both side arm frames generally is not considered.
However, in a practical inspection process, it still requires the moving speeds of both side arm frames to conform to each other when the gantry arm frame moves on the fixed rails. If the moving speeds of both side arm frames are different, the gantry arm frame is subjected to a force and deforms. Although the deformation of the gantry arm frame may be very small, it still produces a big influence on the accurate radiation detection system. Once the gantry arm frame deforms, the radiation detector cannot receive the full ray, and thus the imaging quality will be deteriorated. Thereby, it is necessary to control a position error between the both side arm frames by means of an automatic deviation correction system during movement of the gantry arm frame on the fixed rails, so as to obtain an accurate scan image.
In the prior art, the deviation correction of the gantry arm frame is mainly achieved by a manual operation, and there is not a deviation correction means and a synchronous control means. Because of an actual mechanical manufacturing error, a motor rotation speed error, etc., the effect of the manual deviation correction is not ideal. So, it is necessary to improve the deviation correction of the gantry arm frame in the prior art.